RATIONALE FOR AXILLARY DISSECTION
There are three reasons to do axillary dissection: regional control, staging and to improve survival. For staging, we have got enough literature from around the world to tell us the accuracy of sentinel node biopsy. For regional control, surgery results in almost 100% control, as does radiation therapy, so before we abandon something that works very well, we have to be very careful. We don't have any long-term data on regional control for sentinel node biopsy. Regarding the issue of survival — and I know it is a little heretical to say this — there may be a survival advantage in controlling the axilla. The few studies that looked at this were done in an era when we randomized hundreds of patients, not thousands of patients. So the statistical power was not there.
I've personally never done a sentinel node procedure in a breast cancer case outside of a clinical trial. I'm not going to say that it shouldn't be done — this is a judgment call. But in terms of making the claim that sentinel node is as good as axillary dissection, we don't have the data and we are in an era of evidence-based medicine.

—David Krag, MD

RATIONALE FOR ACOS Z-11
Many surgeons believe that axillary dissection is therapeutic, and they are reluctant not to perform axillary dissection in sentinel node-positive patients.
However, a number of randomized studies have failed to show that axillary dissection improves survival. In sentinel node-positive women, the sentinel node may be enough because often it's the only involved node.
In addition, virtually all node-positive women in this country receive adjuvant systemic therapy, which may take care of any residual problem in the axilla. Many patients are also receiving opposed tangential field radiation, and that's partial axillary radiation. In studies where patients received lumpectomy with radiation and no axillary dissection, the axillary recurrence rate was extraordinarily low. I think ACOS Z-11 is a very important, very justifiable and ethical trial. For an operation that's been used for 100 years, it's time to answer the question about the need for axillary dissection.

—Armando Giuliano, MD

CLINICAL TRIALS OF SNB
NSABP trial B-04 showed no difference in survival outcome between axillary dissection at the time of diagnosis and delayed axillary dissection if clinically positive nodes developed. Since that trial didn't show a survival difference, is it reasonable to expect that NSABP B-32 would? I think that's a very open question. However, B-32 will tell us about the clinical false-negative rate when lots of surgeons do sentinel node biopsy, which is an important issue to inform patients about.
The ACOS trial addresses the much more controversial question of whether there is a reason to remove axillary nodes after the patient has been staged as node-positive. It challenges the dogma that people have had for years.

—Monica Morrow, MD

ACCRUAL TO SENTINEL NODE TRIALS
Sentinel node mapping is becoming a victim of its own success. As surgeons realize that it is not a terrific technical feat to learn how to do this, and as more patients become aware of it through the Internet and other sources, it will become harder and harder to find both patients and physicians willing to participate in randomized clinical trials.

—Patrick Borgen, MD